Surgical tables have two main tilting movements. One into the longitudinal axis of the table which is called Trendelenburg and Anti-Trendelenburg movement and one in the lateral direction which is called lateral movement. Manufacturers try to achieve high large movement range for all these movements. At the same time they would like to lower the lowest possible position as well as increase the highest possible position of the table.
A Cardan hinge is typically placed in the center of the table. Then two actuators are used, one for Trendelenburg/Anti-Trendelenburg and one for the lateral movement. A Cardan Hinge is a joint or coupling in a rigid rod that allows the rod to ‘bend’ in any direction, and is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, rigidly connected by a cross shaft. The universal joint is not a constant-velocity joint.